Needle design for live microorganisms

ABSTRACT

The present invention seeks to provide an improved needle design and needle assembly which is particularly adapted for live cell vaccines and the like. More specifically, the needle assembly includes a gap filler with an inner funnel which is specifically shaped and adapted to fill a turbulence gap naturally formed between a conventional needle retainer and syringe. By maintaining a laminar flow of the fluid, the turbulence and the destruction of live cells are reduced. Additionally, some of the needle designs include a funnel-shaped mouth which is utilized during the filling of the syringe to minimize physical damage to the cell wall or membrane of the live cells otherwise caused by the sharp edges at the tip of a standard injection needle. A breakaway needle assembly is also disclosed.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to improved needle designs for livevaccines and, in particular, live vaccines for Marek's and otherdiseases affecting chicken and other avian species, as well as for livemicroorganisms in general. More specifically, the present inventionrelates to a pair of needle assemblies having a needle and needleretainer which minimizes turbulence and damage to the live cells duringtransfer of vaccine fluids into and out of a standard syringe.

[0003] 2. Prior Art

[0004] Marek's disease is a viral disease of chickens resulting in atype of cancer, and is one of the most serious threats to poultryhealth. This virus lies latent in T-cells, which are a type of whiteblood cells. T-cells are an integral part of the immune system responsewhich is the bird's natural defense against disease. Within three weeksof infection, the fatal virus manifests as aggressive tumors in thespleen, liver, kidney, gonads, skin and muscle of the infected bird.

[0005] Marek's disease is a herpesvirus-induced lymphoprolifertivedisease that occurs naturally in chickens. Since the advent of theturkey herpesvirus vaccine (HVT), newly hatched chicks have beenroutinely inoculated against the disease prior to being placed in thebrooder houses. Although HVT vaccine is generally quite effective,occasionally inoculated flocks experience heavy Marek's disease losses.More recently, it has been found that by proper selection of both thesite and time of inoculation, embryonic vaccination can be effective inthe control of poultry diseases. It is essential that the egg beinjected during the final quarter of the incubation period, and that theinoculate be injected within either of the regions defined by the amnionor the yolk sac. Under these conditions, the embryo will favorablyrespond immunologically to the vaccine with no significant impairment ofits prenatal development.

[0006] A live cell-associated virus vaccine of tissue culture origintypically contains the Rispens strain, the SB1 strain of the chickenherpes-virus and the FC 126 HVT strain of the turkey herpes virus aloneor in combination. The vaccine is presented in glass ampules containingconcentrated vaccine, typically 1000 doses each, with a specified titerdefined as Plaque Forming Units (“PFUs”). The vaccine product is storedin a frozen condition typically in liquid nitrogen freezer and shippedin liquid nitrogen. A special sterile diluent is supplied in a separatepackage, typically a sealed plastic bag with appropriate injection portand delivery tube opening. The vaccine is reconstituted by thawing thefrozen vaccine in the glass ampule. The ampule is then broken open andthe liquid vaccine product is withdrawn from the ampule using a standardneedle and syringe. The diluent is stored at room temperature until afew hours prior to use when the concentrated vaccine product withdrawnfrom the ampule by the needle and syringe is then injected into thediluent contained in the sealed plastic bag through the bag injectionport. The reconstituted vaccine is then ready for delivery from thesealed bag through the delivery tube.

[0007] There are various factors that affect the level of PFUs deliveredby a live cell vaccine, such as Marek's vaccine, to an inoculatedspecimen. Most of these factors occur during the vaccine reconstitutionand in the delivery process and both have to do with vaccine handling,temperature, turbulence in the syringe, air pressure, friction, pH,vaccine delivery tube, length and diameter, needle length and diameter,needle shape and delay in vaccine consumption after thawing. Eliminationor reduction of the adverse effects arising from any one of these notedfactors would greatly improve the inoculation process for Marek'svaccine, specifically, and for live cell vaccines, generally.

[0008] A conventional needle configuration for drawing a vaccine fluidinto a syringe and subsequently delivering the vaccine from the syringeto a vaccine delivery system, such as an automated injection system foravian embryos as disclosed in U.S. Pat. No. 4,681,063, is illustrated inFIG. 1. As shown, a conventional syringe needle, generally designated byreference numeral 110, is attached to a conventional syringe, generallydesignated by reference numeral 112. The syringe 112 has a hollowtubular barrel 114 having a chamber 116 for retaining fluid, such as thelive vaccine. The syringe 112 also has a plunger with a flexible plug(not shown). As is common in the art, the plug will sealingly engageagainst an inner surface 118 of the syringe barrel 114, with the plungerbeing pulled out of the chamber 116 to draw fluid into the chamber andbeing pushed into the chamber 116 to inject fluid out of the chamber.

[0009] The syringe 112 has a standard tubular extension 120 projectingfrom end 122 of the barrel 114. The tubular extension 120 has acylindrical axial passageway 126 which communicates with the syringechamber 116 and needle assembly 110, when attached. The tubularextension 120 is surrounded by a collar 124 which has internal malethreads 125 so that the needle assembly 110 can be sealingly attached ina conventional manner by outwardly extending flange 138 screwingdownwardly on threads 125.

[0010] The needle assembly 110 includes an injection needle 133 and aneedle retainer 128. The retainer 128 is mounted on the forward end ofthe syringe 112 as previously described to retain the needle assembly110 in generally axial alignment with the syringe 112 and tubularextension 120. The needle 133 is made of conventional needle materials,such as stainless steel for strength and chemical compatibility, and theretainer 128 is preferably made of a suitable plastic material which canbe easily molded around the end 136 of needle 133.

[0011] The needle 133 includes a hollow central passageway 134 and asharpened tip 130 at its outer end 132 formed by an angled cut of thehollow needle. The needle 133 is preferably surrounded by a cap orsheath (not shown) before the needle is used for sterility, and thesheath is easily removed in a conventional manner when the needle andsyringe are ready for use.

[0012] To hold the needle assembly 110 in generally axial alignment withthe syringe, the retainer 128 has an axial bore 141 and an outwardlyprojecting rim or flange 138 at the syringe receiving end. The axialbore 141 is sized to fit in sealing engagement over the tubularextension 120, while the outer circumference of the rim or flange 138engages the threads 125 on the inner wall of surrounding collar 124. Asassembled, the outwardly projecting rim or flange 138 snugly fits downinto space 139 between the outer surface of the tubular extension 120and the inner surface of the collar 124. Thus, mounted on the syringe112, the hollow central passageway 134 of the needle portion 133 alignswith the passageway 126 of the tubular extension 120 and the chamber 116of the syringe 112.

[0013] The conventional syringe and needle assembly as previouslydescribed and shown in FIG. 1 is commonly used and well known. Theassembly is particularly intended for single dosage use, and forstorage, transportation, and injection while filled with fluid. It isalso the standard assembly for transferring concentrated live virusvaccines, such as Marek's vaccine, from supply ampules to diluentstorage containers or bags where it is appropriately diluted fordelivery to a specimen to be vaccinated, such as chicken egg embryos andthe like, by known vaccine delivery machines or systems. It has beensurprisingly discovered that the use of this conventional syringe andneedle assembly for transferring live vaccines creates unexpectedproblems in the destruction of the live cells caused by turbulence ofthe vaccine during both the drawing of the vaccine into the syringechamber 116 and the discharge of the vaccine from the chamber 116,through the passageway 126 of extension 120 and the passageway 134 ofthe needle 133.

[0014] While it was known that turbulence could be detrimental to thelive cell count of various vaccines, including Marek's vaccine, it wasnot appreciated that the conventional syringe and needle assembly ascommonly used for transfer of these vaccines would cause significantturbulence and that this turbulence could significantly reduce the livecell count, or the PFUs of the vaccine, including Marek's vaccine, bothduring the filling of the syringe barrel 114 and during injection of thevaccine out of the syringe.

[0015] The problem with this commonly used needle and syringe assemblyis that a tubular gap, indicated by numeral 140 in FIG. 1, is formedbetween the top of the tubular extension 120 and the rear part 136 ofthe needle 110. It has been found that this tubular gap 140 causesturbulence in the fluid flowing between needle 133 and tubular extension120, both during the filling of the syringe barrel 114 and during theinjection of the vaccine from the syringe.

[0016] To understand the effect of turbulence in the context of thepresent invention, it is believed that a brief discussion of flowingfluid would be helpful. When fluid flows slowly and smoothly, the flowis called laminar. At fast velocities, however, the inertia of the fluidovercomes fluid frictional forces and turbulent flow results. When afluid is flowing this way, it flows in eddies and whorls (vortices), andthere is much more drag than when the flow is laminar.

[0017] Turbulence is composed of eddies: patches of zigzagging, oftenswirling fluid, moving randomly around and about the overall directionof motion. Technically, the chaotic state of fluid motion arises whenthe speed of the fluid exceeds a specific threshold, below which viscousforces damp out the chaotic behavior. As applied to live cell vaccines,such as Marek's vaccine, turbulence that disrupts the flow causes thelive cells to bounce off one and another. This bouncing during theturbulence kills live cells, thus reducing the PFUs which can bedelivered by the vaccine.

[0018] Upon studying the conventional syringe and needle assembly, ithas also been determined that damage to the live cells of theconcentrated vaccine also occurs at the outer end 132 of the needle 133due to the sharpened tip 130 during the drawing of the vaccine into thesyringe barrel 114. The live cells of known vaccines for inoculatingchicken and other avian species embryos, including Marek's vaccine, aswell as the live cells in many other live cell fluids are very fragile.Damage to the outer membrane or cell wall can cause rapid destruction ofthe live cell. It has been found that the sharp edges of the needle tiptend to physically damage the cell wall or membrane of the live cellswhen drawn into the needle. This damage can be very detrimental to thelive cells in known vaccines, particularly Marek's vaccine, andsubstantially reduce the PFUs which can be delivered.

SUMMARY OF THE INVENTION

[0019] In view of the turbulence generated by conventional needledesigns and the sharp needle tip, as well as other problems anddisadvantages of the prior art, the present invention seeks to provideimproved needle designs and needle assemblies which are particularlyadapted for transferring concentrated live cell vaccines and otherfluids containing live cells. More specifically, the needle assembliesof the present invention are specifically shaped and adapted to fill thetubular gap between the needle retainer and the syringe to reduce theturbulence and destruction of the live cells of the vaccine, thusdelivering higher PFU values. Additionally, the present inventionincludes a needle design which is utilized during the filling of thesyringe to minimize the physical damage to the live cells of vaccinesand other fluids caused by the sharp edges at the tip of the needle.

[0020] In order to minimize the turbulence and promote a laminar flow ofthe concentrated vaccine, and to minimize physical damage to the livecells, the needle assemblies of the present invention modify thestandard needle structure in two important ways.

[0021] First, the needle retainer 128 is modified to include an insertor filler to fill the gap 140 while at the same time providing an axialpassageway to connect passageway 126 of the syringe tubular extension120 with the entrance to the passageway 134 of the needle 133. The axialpassageway of the gap insert or filler is designed to provide a smoothflow transition between the larger diameter extension passageway 126 andthe smaller diameter needle passageway 134. The insert or filler issized so that the end facing the outer surface 145 of the extension 120sealingly abuts the surface 145 when the needle retainer 128 is screwthreaded into collar 124 and the axial bore 141 reaches tight sealingengagement around syringe extension 120. In order that the fluid canhave a continuous laminar flow, the gap insert or filler has an innerthroughbore which is preferably funnel or conically shaped. The topopening of the throughbore is substantially equal in diameter to therear opening of the needle, and the rear opening of the throughbore issubstantially equal in diameter to the opening of the syringe extensionpassageway. Thus, the live cells are not bouncing around in the gap 140and turbulence is minimized.

[0022] Second, a different needle tip is used for drawing theconcentrated vaccine from the ampule, in particular, a needle tip havinga funnel shape to form an open mouth at the entrance end of the needle133. With this funnel shape, the needle end can more gently draw thevaccine into the hollow needle passageway 134 without damage to the cellwall caused by the sharp edges of pointed tip 130. Since damage to thecell wall is minimized, the destruction of the live cells is reduced andeach dosage of vaccine has higher PFUs to vaccinate the embryos.

[0023] A needle with an open mouth in accordance with the presentinvention can be used when drawing the concentrated vaccine up from theampule because the ampule has an opening for withdrawing the vaccinetherefrom and does not need to be punctured by a sharp needle tip. Onthe other hand, when delivering the concentrated vaccine to a deliverysystem, it is typically desirable to puncture the container containingthe vaccine diluent, through the injection port, or the container forholding the diluted vaccine for delivery to the avian embryos. In suchcircumstances, the needle tip must have a sharpened point such as usedin the standard needle configuration. However, when delivering theconcentrated vaccine from the syringe through the needle portion, thevaccine does not encounter the sharp edges at the needle tip, incontrast to drawing the concentrated vaccine into the needle. Hence, thestandard needle tip does not cause significant disadvantages during thedelivery of the concentrated vaccine into the diluent bag or othercontainer.

[0024] In one embodiment of the present invention the needle retainer ismodified with the requisite insert or filler to provide a smooth laminarflow between the needle and the syringe. The needle also has a funnelshape to form an open mouth at its tip. The needle is further modified,however, to have a breakaway tip so that after the concentrated vaccinehas been drawn into the syringe through the open mouth, the outerextremity of the needle can be broken away to leave a sharp point needletip for subsequently injecting the concentrated vaccine into the diluentbag or other container. The breakaway tip is formed by adiagonally-positioned weakened area in the needle near the tip. Theweakened area can be molded into the needle, if the needle is made fromplastic, or scored or ground into the needle outer surface if the needleis made from metal.

[0025] It is therefore an object of the present invention to provide aneedle assembly which can be assembled on a conventional syringe andwhich minimizes the turbulence imparted to a concentrated vaccine,especially a vaccine containing live cells, so as to avoid destructionof the live cells during transfer of the vaccine using the needle andsyringe assembly.

[0026] Another object of the present invention is to provide a needleassembly in accordance with the preceding object and which includes aneedle retainer having a tubular insert or filler with an inner funnelor conical shaped throughbore such that the opening adjacent the rear ofthe needle has a diameter substantially equal to the needle diameter andthe opening adjacent the syringe extension has a diameter substantiallyequal to the diameter of the extension passageway.

[0027] A further object of the present invention is to provide a needleassembly for attachment to a conventional syringe which has a needle tipthat serves to reduce the physical damage imparted to the live cellscontained in a concentrated vaccine or other fluid during the drawing ofthe vaccine into the syringe.

[0028] A still further object of the present invention is to provide aneedle assembly in accordance with the preceding object in which theneedle tip has an open mouth with the mouth diameter larger than thediameter of the needle passageway.

[0029] Still another object of the present invention is to provide aneedle assembly in accordance with the preceding objects which has aneedle tip that serves to reduce the physical damage imparted to thelive cells contained in a concentrated vaccine or other fluid during thedrawing of the vaccine into the syringe and has a breakaway needleconfiguration which, upon removal of the needle end, leaves a sharpenedneedle tip of standard configuration.

[0030] A final object of the present invention to be set forth herein isto provide needle assemblies which can be installed on a conventionalsyringe and which will conform to conventional forms of manufacture, beof simple construction and easy to use so as to provide needleassemblies that are economically feasible, highly strong and durable,and relatively trouble-free in use.

[0031] These together with other objects and advantages which willbecome subsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

[0032]FIG. 1 is a partial cut away side view illustrating a conventionalneedle assembly installed on the end of a conventional syringe;

[0033]FIG. 2 is a partial cut away side view illustrating a needleassembly in accordance with the present invention installed on the endof a conventional syringe for transferring live cell vaccines and otherfluids, and including a modified needle tip to have an open mouth;

[0034]FIG. 3 is an enlarged cut away side view of FIG. 2 illustratingone embodiment of the open mouth needle tip of the present invention;

[0035]FIG. 4 is another enlarged cut away side view of FIG. 2illustrating another embodiment of the open mouth needle tip of thepresent invention;

[0036]FIG. 5 is another enlarged cutaway side view illustrating afurther embodiment of an open mouth needle tip of the present invention;

[0037]FIG. 6 is a partial cutaway side view illustrating a needleassembly of the present invention installed on the end of a conventionalsyringe, except the needle tip is the standard piercing design; and

[0038]FIG. 7 is a partial cutaway side view illustrating a furtherneedle assembly in accordance with the present invention installed onthe end of a conventional syringe for transferring live cell vaccinesand other fluids, and including a breakaway needle tip.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0039] Although preferred embodiments of the present invention areexplained in detail, it is to be understood that the embodiments aregiven by way of illustration only. It is not intended that the inventionbe limited in its scope to the details of construction and arrangementof components set forth in the following description or illustrated inthe drawings. Also, in describing the preferred embodiments, specificterminology will be resorted to for the sake of clarity. It is to beunderstood that each specific term includes all technical equivalentswhich operate in a similar manner to accomplish a similar purpose.

[0040] Referring now to FIG. 2, there is shown a needle assembly,generally designated by reference numeral 210, assembled in aconventional manner on the end of a conventional syringe, generallydesignated by reference numeral 212. The syringe 212 has a hollowtubular barrel 214 with a chamber 216 for receiving and retaining fluid.The needle assembly 210 is used in accordance with the present inventionto draw fluid, especially live cell vaccines such as Marek's vaccine,into syringe barrel 214. The syringe 212 also has a plunger with aflexible plug (not shown). As is common in the art, the plug willsealingly engage against inner surface 218 of the syringe barrel 214,with the plunger being pulled out of the chamber 216 to draw fluid intothe chamber 216 through the needle assembly 210.

[0041] The syringe 212 has a standard tubular extension 220 projectingfrom end 222 of the barrel 214. The tubular extension 220 has acylindrical axial passageway 226 which communicates with the syringechamber 216 and needle assembly 210, when attached. The tubularextension 220 is surrounded by a collar 224 which has internal malethreads 225 so that the needle assembly 210 can be sealing attached inthe conventional manner by outwardly extending flange 238 screwingdownwardly on threads 225.

[0042] The needle assembly 210 includes a needle 233 and a needleretainer 228 at the attaching end for assembly on the forward portion ofthe syringe 212 in the conventional manner so that the needle 233projects from the syringe 212. The needle 233 is made of conventionalneedle materials, such as metal or plastic, and the needle retainer 228is also made from conventional needle retainer materials, such asaluminum or plastic which can be readily molded onto the end of theneedle 233.

[0043] The needle 233 includes a unique tip 230 at its forward end 232,described below, and has a hollow center passageway 234. When packaged,the needle 233 is preferably encased in a cap or sheath (not shown) forsterility, that is removably attached in a conventional manner to theexterior of the retainer assembly 228. The needle retainer 228 includesa conventional outwardly projecting rim or flange 238 which is screwthreaded downwardly inside the internal male threads 225 on the insidewall of collar 224 which surrounds the tubular extension 220 of syringe212. At the same time, the internal wall of the axial bore 241 at theattaching end of the needle retainer 228 engages the external surface ofthe syringe tubular extension 220 to form a tight seal therewith. Whenmounted on the syringe 212, the center passageway 234 of the needle 233aligns with the passageway 226 of extension 220 and the chamber 216 ofthe syringe.

[0044] Reference is now directed to the needle tip 230 shown in FIG. 2and, in more detail, in FIGS. 3 and 4. It has been found that when aconventional sharp tip needle is used to draw in live cell vaccines fromtheir supply ampules, such as Marek's vaccine, into the chamber 216 ofthe syringe 212, the sharp edges of the needle tip damage the wall ormembrane of the cells, and a number of live cells are destroyed, thusreducing the PFUs level. To minimize this destruction of the live cellsat the tip, an open mouth or funnel-shaped tip, generally designated byreference numeral 260, has been developed.

[0045] The funnel-shaped tip 260 is made of the same material as theremainder of the needle 233 and can be formed thereon in anyconventional manner, such as by conventional mechanical and/or hydraulicequipment. The funnel-shaped tip 260 forms an open mouth 262. In theembodiment shown in FIG. 3, the tip is angularly shaped to form thefunnel-shaped mouth 262. In the embodiment shown in FIG. 4, the funneltip has a gradual curved shape to form the funnel-shaped mouth 262.

[0046] Turning next to the embodiment shown in FIG. 5, this embodimentdiffers somewhat from the needle tips shown in FIGS. 3 and 4. In theFIG. 5 embodiment, an enlarged tip 264 is attached at the end of needle232. The tip 264 is preferably made of the same material as the needle232 and is molded onto the end of the needle 232, if plastic, or weldedon, if metal. The funnel shaped mouth 266 can then be formed in the openend of the enlarged tip 264 by a suitable machining or the like. Withthese funnel shapes in FIGS. 3, 4 and 5, the needle can draw the livecell vaccine or other fluid and funnel it down into the needlepassageway 234 with far less damage caused to the live cells at theneedle tip. Hence, the destruction of live cells, and the reduction ofPFUs in live cell vaccines, are substantially reduced.

[0047] When drawing liquid into the syringe 212, the plunger andflexible plug (not shown) move away from the end 222 of the barrel 214thus pulling the liquid into the needle 210 and through the centerpassageway 234. At this point, the fluid has a laminar flow. As thefluid reaches the rear part 236 of the needle 223, it enters axialthroughbore 252 of a tubular gap filler or insert 250. The tubular gapfiller or insert 250 fills the tubular gap 140 which otherwise would bepresent in conventional assemblies as described in accordance withFIG. 1. The throughbore 252 preferably provides an axial funnel orconical shaped passage.

[0048] This funnel-shaped passage has an upper opening 254 which hassubstantially the same diameter as the hollow center passageway 234 ofthe needle 210, and they are axially aligned. The throughbore 252 has alower opening 256 which is much larger than the upper opening 254 andhas substantially the same diameter as the syringe extension passageway226 to which it is axially aligned, as well. Thus, as the fluid flowsfrom the needle 210, through the throughbore 252 of tubular gap filler250 and into passageway 226, the fluid remains substantially laminar asit continues to move into the chamber 216 of the syringe 212. Since thetubular gap filler 250 maintains the fluid in a laminar flow, very fewlive cells are destroyed by turbulence if the fluid were a live cellvaccine, such as Marek's vaccine.

[0049] The tubular gap filler or insert 250 is sized in the longitudinaldirection so that the lower end sealingly engages the outer surface 245of the syringe tubular extension 220 when the needle assembly 210 isproperly assembled on the end of the syringe 212 as previouslydescribed. While the tubular gap filler or insert 250 is shown in FIG. 2as a separate element inside the bore 241 of the needle retainer 228, itis preferred that the gap filler 250 be molded as a unitary componenttogether with the needle retainer 228 when the retainer 228 is moldedonto the end 236 of the needle 233 while at the same time forming thefunnel-shaped throughbore 252 therein. If the gap filler 250 is aseparate insert element from tubular retainer 228, the insert 250 can bemade of any suitable material, such as plastics or the like. It is sizedto fit snugly at the bottom of the axial bore 241 of the needle retainer228 with the funnel-shaped throughbore 252 properly aligned with theneedle passageway 234 and the tubular extension passageway 226.

[0050] Turning now to FIG. 6, there is shown another needle assemblyembodiment of this invention, generally designated by reference numeral310, which is installed on the conventional syringe 212 shown in FIG. 2.Needle assembly 310 can be used to inject vaccine or other fluids fromchamber 216 of syringe 212. In this embodiment of the invention, thesyringe 212 is also identical to the conventional syringe 112 describedpreviously. The needle assembly 310 in this embodiment includes aninjection needle 333 and a needle retainer 328. The needle retainer 328is identical to needle retainer 228, previously described in connectionwith needle assembly 210 of FIG. 2, and includes an identical tubulargap filler or insert 350.

[0051] However, in this embodiment of the invention, the needle 233 isan injection needle and includes a piercing tip 330 substantiallyidentical to the standard tip 130 previously described for needle 133,as shown in FIG. 1. The piercing tip 330 may be necessary in order toinject the live cell vaccine or other fluid contained in chamber 216into the desired compartment for delivering the vaccine to the bird oravian embryo.

[0052] When the live cell vaccine is being injected from the syringe212, the tubular gap filler 350 and throughbore 352 also eliminateturbulence in this area. The fluid is pushed out of chamber 316 by aplunger (not shown) and into the passageway 326. The fluid then flowsinto the funnel-shaped throughbore 352. The flow of the fluid is slowand smooth. As the fluid travels through the throughbore 352, itcontinues into the center passageway 334 of the needle 310. The fluidthen flows out of the tip 332.

[0053] It has been found that there is considerably less damage to thelive cells when injecting a live cell vaccine or other fluid out of astandard slanted needle tip, such as tip 332 shown in FIG. 5 and tip 132shown in FIG. 1, then when attempting to draw live cell vaccine or otherfluids into the central needle passageway through such a tip. Hence, thedamage imparted to a live cell vaccine which is injected out of syringe212 through tip 332 is minimal and there is very little live celldestruction or reduction of the PFUs. The standard needle tipconstruction as embodied in tip 332 is preferred for injecting the livecell vaccines, such as Marek's vaccine, in as much the sharp piercingpoint 330 may be necessary for transferring the vaccine from the syringechamber 316.

[0054] In transferring live cell vaccines, such as Marek's vaccine, inaccordance with the present invention from their original ampules to acontainer for delivering the vaccine to the birds or other avian embryo,a sterile needle assembly 228 is assembled onto a sterile syringe 212 toform the needle and syringe assembly illustrated in FIG. 2. The needletip 232 is then inserted into the ampule containing the live cellvaccine, and the vaccine is slowly drawn into and through the needle 233in central passageway 234 and then into the syringe chamber 216. Thepresence of the unique open mouthed or funnel-shaped tip 232 on the endof needle 233 and the filler or insert 250 serve to promote laminar flowand reduce turbulence during the syringe filling operation. Once thevaccine in the ampule has been exhausted or the syringe chamber 216 hasbeen filled, the needle assembly 210 is removed from the syringe 212 byturning the tubular retainer 228 to disengage outwardly extending flange238 from the internal male threads 225 on collar 224. A new and sterileneedle assembly 310 is then screw threadedly engaged onto the syringe212, now containing the vaccine in the chamber 216, to form the assemblyshown in FIG. 6. Of course, if a piercing tip 330 is not necessary totransfer the vaccine or other fluid from syringe chamber 216 to thedesired container, it could be possible to use the original needleassembly 210, without substituting the alternate needle assembly 310.

[0055] It is contemplated as part of the present invention that theneedle assemblies 210 and 310 will be provided to the poultry operatorsor vaccine users in pairs as a set. Then, the operator or user will haveone needle assembly corresponding to assembly 210 to draw the vaccinefrom the ampule into the syringe and a second needle assemblycorresponding to assembly 310 to dispense the vaccine out of thesyringe.

[0056] Turning now to FIG. 7, there is shown another needle assemblyembodiment of this invention, generally designated by reference numeral410, which includes a breakaway needle. The needle assembly 410 can beused to draw concentrated live cell vaccines or other fluids intochamber 216 of the syringe 212 as well as inject the vaccine or otherfluids from the syringe 212. In this embodiment of the invention, thesyringe 212 is also identical to the conventional syringe 112 previouslydescribed, and the needle assembly 410 includes a needle 433 and aneedle retainer 428. The needle retainer 428 is identical to needleretainers 228 and 338, previously described in connection with needleassemblies 210 and 310 of FIGS. 2 and 6, and includes an identicaltubular gap filler or insert 450.

[0057] The needle 433 includes a weakened area 460 near the outer tip432 which divides the needle 433 into a main needle portion 462 and aremovable needle end 464. The weakened area 460 is at a sharp diagonalto the longitudinal axis of the needle such that upon removal of theremovable needle end 464, the main needle portion 460 is left with asharp pointed needle tip 466, preferably of standard configuration. Theweakened area 460 can be molded into the wall of the needle, if theneedle 433 is molded from plastic, or the weakened area 460 can bescored or ground on the outer surface of the needle, or otherwise formedin the needle wall, if the needle 433 is made of metal.

[0058] When using the needle assembly 410 in conjunction with syringe212, live cell vaccines, such as Marek's vaccine, or other live cellfluids can be drawn into syringe chamber 216 through the open mouth 462of the funnel shaped tip 460 without encountering the sharp edgesnormally associated with a standard needle tip. Once the vaccine orother fluid has been drawn into the syringe chamber 216 with the smoothtransition flow provided by insert or filler 450, the needle breakawayend 464 can be detached from main needle portion 462 along weakened area460. This leave main needle portion 462 with a standard piercing needletip 466 which can be used to pierce an injection port of a standarddiluent bag or other container for injecting the vaccine or other fluidfrom the syringe chamber 216 out through the needle tip 466.

[0059] While the needle assemblies of the present invention have beendescribed specifically for use with live cell vaccines and other fluidsin general, and Marek vaccine in particular, the needle assemblies havebroad application. It is contemplated that the needle assemblies of thepresent invention could be used with Probiotics (Lactobacillus) or anyother microorganism in a fluid suspension. Additional uses could be withsperm and blood cells, or any other live cell fluid or live organismthat might be injured or destroyed by turbulence or sharp edges of astandard needle assembly.

[0060] The foregoing is considered as illustrative only of theprinciples of the invention. Further, since numerous modifications andchanges will readily occur to those skilled in the art, it is notdesired to limit the invention to the exact construction and operationshown and described, and, accordingly, all suitable modifications andequivalents may be resorted to, falling within the scope of theinvention.

What is claimed is:
 1. A needle assembly for live vaccines, said needleassembly comprising: a hollow needle having a rear opening; a needleretainer surrounding said rear opening for frictionally fitting saidhollow needle to a standard syringe in axially alignment, a gap beingnaturally formed between said standard syringe and said rear opening;and a gap filler filling said gap and having a throughbore substantiallyaligned with said rear opening and an opening in said syringe.
 2. Theneedle assembly as recited in claim 1, wherein said hollow needleincludes a sharpened tip.
 3. The needle assembly as recited in claim 1,wherein said gap filler is tubular.
 4. The needle assembly as recited inclaim 3, wherein said needle rear opening is circular and saidthroughbore has a funnel shape with one opening of said throughborehaving a diameter substantially equal to said rear opening diameter andanother opening having a diameter greater than said rear opening andsubstantially equal to said opening in said syringe.
 5. A needleassembly for live vaccine, said needle assembly comprising: a hollowneedle having a distal end defining a generally circular mouth openingsubstantially perpendicular to a longitudinal axis of said needle and arear end with a rear opening, said mouth opening being larger than saidrear opening; and a needle retainer securely receiving said rear part ofsaid hollow needle for frictionally fitting said needle to a syringe. 6.The needle assembly as claimed in claim 5, wherein said distal end isfunnel-shaped to form said mouth.
 7. The needle assembly as claimed inclaim 6, wherein said distal end is angularly shaped to form saidfunnel-shaped mouth.
 8. The needle assembly as claimed in claim 6,wherein said distal end is gradually curved to form said funnel-shapedmouth.
 9. The needle assembly as claimed in claim 5, wherein said needleretainer includes a gap filler between said needle rear end and saidsyringe to reduce the turbulence of said live vaccine flowing throughsaid needle.
 10. The needle assembly as claimed in claim 9, wherein saidneedle rear opening is circular and said gap filler includes afunnel-shaped throughbore with one opening having a diametersubstantially equal to said rear opening diameter and another openinghaving a diameter greater than said rear opening and substantially equalto an inlet opening in said syringe.
 11. A needle assembly for livevaccine, said needle assembly connecting to a conventional syringe witha hollow tubular barrel for retaining fluid, a tubular extensionprojecting from the barrel for forming a central passageway with adiameter to communicate with said hollow tubular barrel, said tubularextension being surrounded by a securing collar, said needle assemblycomprising: a hollow needle having forward and rear ends with said rearend forming an opening with a rear diameter smaller than said diameterof said extension passageway; a needle retainer securely receiving saidrear end of said needle for mounting said needle to said syringe byfrictionally fitting between said tubular extension and said collar withsaid extension passageway and said hollow needle being axially aligned,and forming a tubular gap between said extension passageway and saidneedle rear end, said tubular gap having a diameter greater than saidextension passageway diameter; and a tubular gap filler having athroughbore with a funnel shape with one opening having a diametersubstantially equal to said needle rear diameter and another openinghaving a diameter substantially equal to said extension passagewaydiameter.
 12. The needle assembly as recited in claim 11, wherein saidneedle forward end forms a sharpened tip.
 13. The needle assembly asclaimed in claim 11, wherein said needle forward end is funnel-shaped toform an open mouth.
 14. The needle assembly as claimed in claim 13,wherein said needle forward end is angularly shaped to form saidfunnel-shaped mouth.
 15. The needle assembly for live vaccines asclaimed in claim 13, wherein said needle forward end is gradually curvedto form said funnel-shaped mouth.
 16. A needle set for attachment to atubular extension of a standard syringe to transfer a concentrated livecell vaccine from an ampule for dilution which comprises a first andsecond needle assembly each having a hollow needle and a retainer moldedon one end of the needle to attach said needle assembly to said syringetubular extension, each said needle assembly having a smooth interiorpassageway continuous from said hollow needle into said tubularextension to promote laminar flow and minimize turbulence in saidvaccine when flowing between said hollow needle and said tubularextension.
 17. The needle set as recited in claim 16, wherein saidhollow needle of one of said first and second needle assemblies has adistal end defining a generally circular mouth opening substantiallyperpendicular to a longitudinal axis of said needle.
 18. The needleassembly as claimed in claim 16, wherein said retainer includes a gapfiller having a throughbore to form said smooth interior passagewaycontinuous between an adjacent opening in said hollow needle and anadjacent opening in said tubular extension spaced from said hollowneedle opening.
 19. A needle assembly for vaccines and other fluidscontaining live cells which comprises: a hollow needle having a distalend with a generally circular mouth opening substantially perpendicularto a longitudinal axis of said needle and a rear end with a rearopening, said mouth opening being larger than said rear opening; aneedle retainer securely receiving said rear part of said hollow needlefor frictionally fitting said needle to a standard syringe and having asmooth interior passageway to promote laminar flow and minimizeturbulence between said hollow needle and said syringe; and said hollowneedle having a weakened area to break away said distal end leaving asharpened tip on said needle.
 20. A syringe and needle assembly totransfer a concentrated vaccine or other fluid containing live cellswhich comprises a syringe having a tubular extension, a needle assemblyhaving a hollow needle and a retainer molded on one end of the needle toattach the needle assembly to the syringe tubular extension, saidsyringe and said needle assembly having a smooth interior passagewaycontinuous from said hollow needle into said tubular extension topromote laminar flow and minimize turbulence when said vaccine or otherfluid is flowing between said hollow needle and said syringe.
 21. Amethod of transferring vaccines or other fluids containing live cells bymeans of a syringe and needle assembly which comprises drawing saidfluid into said syringe through said needle assembly while minimizingturbulence and physical damage to said live cells entering said hollowneedle and injecting said fluid out of said syringe through said needleassembly while minimizing turbulence in said fluid when flowing out ofsaid needle assembly.